Native, introduced, and invasive

Native is a relationship to place

Native does not mean that every population belongs everywhere within a country. It describes occurrence in a particular area or ecosystem as a result of natural processes. A species can therefore be native in one watershed, island, or region and non-native in another, even when both places fall within the same political boundary. [1][5]

Separate range from arrival pathway

Current U.S. federal language defines non-native by location outside an organism's natural range and introduction by intentional or unintentional human-caused movement into an ecosystem where it is not native. Other authorities and ordinary usage may group introduced, non-native, nonindigenous, and alien differently. Establishment means a population persists; it does not by itself describe abundance or ecological effect. [1][3][4][5]

Invasive adds a harm test

The current U.S. federal definition, amended by Executive Order 13751, describes a non-native organism whose introduction causes or is likely to cause economic or environmental harm, or harm to human, animal, or plant health. That makes non-native and invasive non-interchangeable terms. Other authorities may frame harm, evidence thresholds, and regulated species differently, so use their current definition when a decision has legal or management consequences. [1][2][4]

Verify the label before repeating it

Ask four questions: What exact geographic unit is being discussed? Did people assist the movement? Is the population established? What documented harm and authority support the invasive designation? Also distinguish natural range expansion from human-assisted introduction. For reporting or management, consult the current local agency list rather than acting from a generic global label. [1][2][3][5]

Related guides

• What “endemic” means
• How to read a species range map